The present invention is directed to bearing assemblies generally, and in particular, to those of the type commonly used as clutch release bearings in automobile friction disc clutches.
Two common problems in the clutch release bearing art are: (1) eccentricity of the bearing axis (transmission input shaft axis) relative to the engine flywheel axis, and (2) an out-of-square condition between the clutch release levers and the bearing. "Out-of-square"is a familiar term used in the art to describe a condition whereby the plane defined by the tip of the clutch release levers or fingers is not parallel to the plane of the bearing face which they engage. The first problem results in undue wear between both the bearing face and the tips of the clutch levers because of the reciprocating motion therebetween which takes place after engagement and prior to the bearing and clutch disc rotating as one unit. The second problem results in undue wear occuring on one particular clutch release lever during one particular clutch release. In other words, the entire axial load exerted while depressing the clutch, which is generally in the order of 500 pounds, is exerted by one clutch finger, or at any rate, less than all clutch fingers, and when this occurs, in an eccentrically mounted bearing assembly, the amount of wear caused by the reciprocating motion between that particular clutch finger and the bearing face is significantly increased over what it would be were it not in the out-of-square condition. These two problems are the result of variations in tolerences arising from currently practiced manufacturing and assembly techniques for the complete clutch and transmissions, and it is not considered economically practical to try to further control these variances.
It has heretofore been proposed to compensate for such misalignment problems by increasing localized loading, introducing bending or over-turning moments, and by allowing oscillatory scrubbing between mating parts of the clutch assembly. These prior art techniques, however, increase the rate of wear, introduce noise and vibration, and generally reduce the life of the clutch assembly.
The clutch release bearing assembly of the present invention overcomes the problems and disadvantages associated with prior art constructions by automatically compensating for deviations in misalignment resulting in improved durability of the clutch assembly and reduced noise and vibration.